Table of Contents
pnmtopalm - convert a portable anymap into a Palm pixmap
pnmtopalm
[-verbose] [-depth N] [-maxdepth N] [-colormap] [-transparent color] [-offset]
[-rle-compression|-scanline-compression] [pnmfile]
Reads a PNM image
as input, from stdin or pnmfile. Produces a Palm pixmap as output.
Palm
pixmap files are either greyscale files 1, 2, or 4 bits wide, or color
files 8 bits wide, so pnmtopalm automatically scales colors to have an
appropriate maxval, unless you specify a depth or max depth. Input files
must have an appropriate number and set of colors for the selected output
constraints. This often means that you should run the PNM image through
ppmquant before you pass it to pnmtopalm. Netpbm comes with several colormap
files you can use with ppmquant for this purpose. They are palmgray2.map
(4 shades of gray for a depth of 2), palmgray4.map (16 shades of gray
for a depth of 4), and palmcolor8.map (232 colors in default Palm colormap).
- -verbose
- Display the format of the output file.
- -depth N
- Produce a
file of depth N, where N must be either 1, 2, 4, 8, or 16. Any depth
greater than 1 will produce a version 1 or 2 bitmap. Because the default
Palm 8-bit colormap is not grayscale, if the input is a grayscale or monochrome
pixmap, the output will never be more than 4 bits deep, regardless of the
specified depth. Note that 8-bit color works only in PalmOS 3.5 (and higher),
and 16-bit direct color works only in PalmOS 4.0 (and higher). However, the
16-bit direct color format is also compatible with the various PalmOS 3.x
versions used in the Handspring Visor, so these images may also work in
that device.
- -maxdepth N
- Produce a file of minimal depth, but in any case
less than N bits wide. If you specify 16-bit, the output will always be
16-bit direct color.
- -offset
- Fill in the nextDepthOffset field in the file
header, to provide for multiple renditions of the pixmap in the same file.
- -colormap
- Build a custom colormap and include it in the output file. This
is not recommended by Palm, for efficiency reasons. Otherwise, pnmtopalm
uses the default Palm colormap for color output.
- -transparent color
- Marks
one particular color as fully transparent. The format to specify the color
is either (when for example orange) "1.0,0.5,0.0", where the values are floats
between zero and one, or with the syntax "#RGB", "#RRGGBB" or "#RRRRGGGGBBBB"
where R, G and B are hexadecimal numbers. This also makes the output bitmap
a version 2 bitmap. Transparency works only on Palm OS 3.5 and higher.
- -rle-compression
- Specifies that the output Palm bitmap will use the Palm RLE compression
scheme, and will be a version 2 bitmap. RLE compression works only with
Palm OS 3.5 and higher.
- -scanline-compression
- Specifies that the output Palm
bitmap will use the Palm scanline compression scheme, and will be a version
2 bitmap. Scanline compression works only in Palm OS 2.0 and higher.
palmtopnm(1)
, ppmquant(1)
, pnm(5)
An additional compression format,
packbits, was added with PalmOS 4.0. This package should be updated to
be able to generate that.
Palm pixmaps may contains multiple renditions
of the same pixmap, in different depths. To construct an N-multiple-rendition
Palm pixmap with pnmtopalm, first construct renditions 1 through N-1 using
the -offset option, then construct the Nth pixmap without the -offset
option. Then concatenate the individual renditions together in a single
file using cat.
This program was originally written as ppmtoTbmp.c,
by Ian Goldberg and George Caswell. It was completely re-written by Bill
Janssen to add color, compression, and transparency function.
Copyright 1995-2001 by Ian Goldberg, George Caswell, and Bill Janssen.
Table of Contents